Snettisham Iron Age hoards: technology and analysis

Some of the boxes of Snettisham torcs, wires and metal fragments being examined by microscopy and analysis to survey the range of material for composition and manufacturing technology.

Project leaders: Nigel Meeks, Duncan Hook

Department: Conservation and Scientific Research

Project start: 2003
End date: 2008-9

Other British Museum staff:
Caroline Cartwright, Susan La Niece, Fleur Shearman, Marilyn Hockey, JD Hill, Jody Joy

Other departments: Prehistory and Europe

External partners:
Ian Stead
Peter Northover, Department of Materials, University of Oxford

Description:

The Snettisham treasure is the largest deposit of gold, silver and bronze artefacts dating from the Iron Age found in England. Material from the site was first discovered in 1948, with further hoards, including the ‘Great Torc’, being found in 1950. Then in 1990, another large hoard of approximately 600 fragments was found by a metal detectorist. The site was excavated extensively during 1990-1992, with seven more hoards being recovered.

A combined total of over 200 torcs, over 100 bracelet and ring ‘ingots’, large amorphous ingots, 234 coins and many fragments have been recovered from the site, with a total weight of over 40 kilograms. In addition to its sheer quantity, the metalwork is famous for its quality of artistry and workmanship.

Some investigative cleaning, conservation and semi-quantitative analysis of the metalwork was carried out in the early 1990s as part of the Treasure Trove process. These studies are now being greatly extended using a range of analytical techniques including optical microscopy, scanning electron microscopy (SEM), X-ray fluorescence (XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES).

The fragmentary nature of some of the material also facilitates a thorough investigation of the technology and the methods of manufacture of the torcs. The results of the programme will form part of a major catalogue currently being prepared. The work has already confirmed the use of silver-plating and of mercury-gilding, which appears to be the earliest in Britain, and the identification of charcoal from twigs used as support for twisted wires in construction of some torcs. The work also allows comparisons to be made with other Iron Age and contemporary classical metalwork.

Objectives:

Some of the boxes of Snettisham torcs, wires and metal fragments being examined by microscopy and analysis to survey the range of material for composition and manufacturing technology.

The main aim of the project is to make a representative selection of a wide range of gold, silver and bronze torcs, other artefacts and scrap material from Snettisham and to characterise it in terms of its composition and its manufacturing technology. This will enable the analytical and technological group typologies to be consolidated, provide new information and clarification, and be the scientific basis for future comparisons and research with material from other hoards.

The major objective in terms of publication will be to collaborate with curators to produce a scholarly catalogue on the hoards. Other dissemination will be undertaken at national and international conferences, with the benefit of feedback from world-class scholars, leading to further publications in the proceedings of these conferences.

The opportunity to reach a wider audience will also be taken by contributing to the refurbished display of Snettisham metalwork in Gallery 50 of the Museum.

Publications:

N.D. Meeks, D.R. Hook, S. La Niece, C. Cartwright, ‘Current studies on Celtic torcs, terminals and technology at the British Museum’, in D. Garrow (ed.) Rethinking Celtic Art (Oxbow Books, Oxford), (in prep.).  (Paper presented at a workshop entitled ‘New Approaches to Celtic Art’, Oxford, November 2006)

I.M. Stead, ‘The Snettisham Treasure: excavations in 1990’, Antiquity, 65 (1991), pp. 447-64

R. Rainbird Clarke, ‘The Early Iron Age treasure from Snettisham, Norfolk’, Proceedings of the Prehistoric Society, 20 (1954), pp. 27-86

Images (from top):

  • Inset colour image shows a typical inter-twined mixed group of gold/silver alloy fragments.  The main image is a magnified scanning electron microscope image of a twisted, hammered, square-section bronze torc wire found by analysis to have the remains of mercury gilding on the surface (light areas).
  • Some of the boxes of Snettisham torcs, wires and metal fragments being examined by microscopy and analysis to survey the range of material for composition and manufacturing technology.